Astronomers Announce the First Possible Photo of A Planet Beyond Our Solar SystemSeptember 10, 2004
European and American astronomers working at the Southern European Observatory in Chile announced the first possible photo of a planet and its stellar brown dwarf companion 2M1207 were photographed, opening up the possibility of a great new age in exoplanet discoveries. The photo is based on three near infrared exposures taken by the NACO adaptive-optics facility at the 8.2 m Yepun telescope at the ESO Paranal Observatory. The NACO adaptive optics overcome the distortion induced by atmospheric turbulence, allowing astronomers to observe distant objects as extremely sharp near-infrared images. An essential component of the adaptive optics system, the infrared wavefront sensor senses the deformation of the near-infrared image in a wavelength region where objects like 2M1207 are much brighter than in the visible range. While the astronomer's findings indicate the strong possibility that this photo depicts a young gas planet like Jupiter, further studies will have to be made to come up with definitive proof. On-going studies will include observation of the candidates motion relative to the brown dwarf companion to see if the candidate planet matches that of an orbiting planet. Christophe Dumas, of the SEO, described the thrill of seeing such a faint source of light in real-time on the instrument display and even though much larger than a terrestrial-size object, he felt the strange feeling of possibly seeing the first planetary system beyond our own ever imaged. The distance of the planet is roughly 55 AU, about the same distance as the planet Neptune from our own sun.
Testing the technical limits of the Yepun telescope, the candidate host's companion was 100 times fainter even though the host, a failed star (too light to combust into fusion nuclear reactions in its core) was extremely dim and located at a distance of 230 light years from out solar system. Using high-angular-reslution spectroscopy with the NACO facility the spectrum of the brown dwarf's companion indicated the presence of water molecules and confirmed that the object must be a small and light object. Spectroscopy also indicates the surface of the faint object is about 10 times hotter than Jupiter, which makes sense due to the young age of this solar system when the planet is undergoing the initial contraction phase in its early development. Although young and hot the candidate planet will eventually cool over the course of tens of millions of years to become much like the gas planets in our own solar system. Although evidence strongly suggests that this is truly is an exoplanet, about five times the mass of Jupiter, the data does not indicate a clear picture of the true nature of the object and the astronomers are referring to the object as the "Giant Planet Candidate Companion" (GPCC). It will take anywhere from one to two years to compile the necessary data in order to prove the nature of this discovery and would represent one of the greatest achievements of the astronomical team since the beginning of their work in 1998 when they set out to study the local regions of distant stars.
The ESO will release its findings ("A Giant Planet Candidate near a Young Brown Dwarf" by G. Chauvin et al.) in the journal "Astronomy and Astrophysics". A preprint is available here .